Headlight-lens.



E. F. STEINMAN.

HEADLIGHT LENS.

APPLICATION FILED MAY I.

OQ 1 9 1 m lo d Lw. m R

EDWARD F. STEINMAN, OF CINCINNATI, OHIO.

HEADLIGHT-LENS.

J Specication of Letters Patent.

Patented Jan. 8, 1918.

Application lei May 1, 1917. Serial No. 165,775.

To all 'whom t may concern:

Be it known'that I, EDWARD'F. STEINMAN, residing at Cincinnati, Hamilton county, State of Ohio, have invented certain new and useful Improvements in Headlight- Lenses,3 of whichlthe following.. isia clear, full, and exact.desciiptionfattention being called to the drawing which accompanies this application and forms a part thereof.

This invention concerns lenses for headlights and more particularly lenses which,l are used in connection with headlights for! automobiles. f

Theobject is to construct such a lens in a manner to do away with the objectionable glare thereby rendering the use of dimmers or other means for'this purpose unnecessary.

\ accompanying drawing The invention consists of the construction whereby this object is obtained and as described in the following speeilication and pointed out in the claim at theend thereof.

The construction isalso illustrated in the in which:

Figure 1. shows an axial section of a headlight embodying my invention.'

Fig 2. shows the inner side of a part of the lens used in connection therewith and embodying the features of my invention.

Fig. 3. is a cross-section of a lens of modi ed form.` y

In the drawing, letter A indicates the re- .ilector provided with a suitable light ywhich is not shown,

Letter B indicates the lens positioned at the open end of this reflector and held in place at the annular edge thereof by any suitable means.

It is made of glass by any of the approved methods of manufacture and may be cast, pressed or blown.

In profile it may be dat as shown in Fig. or it may be convex or concave or of a combination of shapes as shown in rFig. 1.

In particular this shape comprises the concave center portion 5 and an annular zonal portion 6 around it and extending to the edge of the reflector.

The particular dimming effect whereby., -the glare is subdued is obtained by a number of concentric annular prisms C which are provided on the inner side of the lens on its 51de next to the light source, .Each one of these prisms'is substantially triangular in cross-section in its protrusion from the body of the lens, and so presented toward the light source thatl both of vits protruding surfaces are impinged by the light waves; and so that the light waves impinging on the radially inward side of the prism will be refracted in vtheir passage through the lens and thence to the outer air in a divergent direction, while the light rays converging on the radially outward' side of each prism will be so retracted that they will be con-V ;'fergent on their emergence from the lens `nto the outer air.` I am thus enabled to secure divergent and convergentrays and to treat each in a dit'erent manner,`if desirable. I prefer to treat'the radially outward sides o so as to reduce the intensity of theconverging rays and to leave the other sides of the prisms fully transparent, so that the diverging rays are not reduced in intensity. This is especially desirable where the lens is used in a vehicle lamp since about one-half of the light will be concentrated in the immediate path of the vehicle, but so diminished in intensity as not to produce glare in the eyes approaching in the opposite direction, while the diverging rays light the sides of the roadway and branching roadways, and are not subdued because they are by the refraction Ydistributed over a large area, and, furthermore, arernot thrown into the eyes of anybody in such proximity to the Ivehicle as to make the glare dangerous eve-n if it should be present in these unsubdu,ed divergent rays.

It may be produced in the formation of I the lens while the same is cast or blown by imparting a rough surface to the pafrticular side of the prisms or it may be fdone by grinding .or sand-blasting or coating,

. etching, stainingv or painting the l'garticular side ot' the prisms by means of a 'substance suitable for the purpose.

These prisms may cover the entire surface.

of the lens or may be onntted frmthe coni.'I itral 'portion thereof as shown in the draw# ang.

tially triangular .cross section in its protrusion from the body of th clined side of each of vs e lens, the inner nald annular prlsms being arranged to diffuse away from -the axis of the lens incident belng arranged to refrac rays and the outer inclined side of each of said annular prisms t incident rays substantial y parallel with the axis of said lens, said ou er inclined faces being/treated lto render them translucent.

In testimony whereof I hereunto ax my 

